Superconductive Bi.sub.2 Sr.sub.2 Ca.sub.1 Cu.sub.2 oxides are known in the art. They are prepared by combining the appropriate precursors in the required proportions, firing the mixture and allowing the mixed oxide to cool.
The product may then be reground and sintered to produce a porous product of superconductive Bi.sub.2 Sr.sub.2 Ca.sub.1 Cu.sub.2 oxide having low current carrying capacity. It is an object of this invention to produce a fiber of superconductive Bi.sub.2 Sr.sub.2 Ca.sub.1 Cu.sub.2 oxide which is less porous and has improved current carrying capacity. This invention also relates to a novel method for producing high current carrying Bi.sub.2 Sr.sub.2 Ca.sub.1 Cu.sub.2 superconductive oxide articles.